Building structure



March 4, 1952 c. A. AJNE BUILDING STRUCTURE 6 Sheets-Sheet 1 Filed Sept. 6, 1944 March 4, 1952 c. A. AJNE BUILDING STRUCTURE 6 Sheets-Sheet 2 Filed Sept. 6, 1944 March 4, 1952 AJNE 2,587,804

BUILDING STRUCTURE Filed Sept. 6, 1944 6 Sheets-Sheet 3 J W 4 QL%ZW l/ M ATTORNEYS "Mach 4, 1952 Filed Sept. 6, 1944 c. A. AJNE 7 BUILDING STRUCTURE 6 Sheets-Sheet 4 March 4, 1952 c. A. AJNE BUILDING STRUCTURE 6 Sheets-Sheet 5 Filed Sept. 6, 1944 March 4, 1952 Filed Sept. 6, 1944 C.A.AJNE

BUILDING STRUCTURE 6 Sheets et 6 &

116 #2 1/4 y a I {44 w 3 k WA WWW zo'e Patented Mar. 4, 1952 Application Sizptemberfi, 1944;--Serial No.-552,927 Ilf'SWedn' 0et0ben30, 1939.5

Section .1, FubIicL'aw 690; August 8,1946 Patent expires Detobr 3011959 eclai'mssl (01. 201-4 The present invention" relates' a building construction comprising a number' ofindividual building sections and to a skeleton keeping said sections together and consistingof a'grld o 'mutually perpendicular joining and coupling bars: Primarily, the invention aims toenable a .satis-" factory connection between the individual sections by means of the skeleton structure, and

particularly has for its 'ob'ject'to construct the various parts includedin the construction so as to obtain an easily. mountable and dismountable structure.

The building sections are rectangular and are adapted to be assembled in edge-to-edge relation by the skeleton to form a wall. Asused. here and in the appended claims, the term wall is intended to include interior and exterior walls.

floors, ceilings, androofs.

The skeleton elements may either consist of bars separated from the building section or consist of parts being at least partly enclosed. in the building sections already before assembling the building. The latter arrangement thus produces a beam-like structure whichis particularly suited to the use in floor and roof structures. A number of such beam-like structures situated sideby side may together form the roof or floor in a.

building, generally no. outer covering on thebuilding section and no particular beams beingzrequired since the beam-like building sections act.

themselves as beams as well as outer. covering. In case of roofs the beam-like sections are. provided with an outer covering adapted to be applied to the blocks in their manufacturein the factory.

The skeleton elements are substantially of two.

types, i. e. joining bars andfcoupling bars. The

joining bars are disposed in a groove in an edgev wherethe joining and coupling bars run together,

and said ends are connected by special" coupling members at this point.

Some embodiments of the invention will be de.-

scribed hereinafter referencebeing had to the.

accompanying drawings wherein:

Fig. 1 is a perspective .view of a building according to the invention,

Fig. 1a, an elevation of a' section of. a wall of the building;

Fig. 1b is an elevation similar to Fig. 1a show- 2* 111g? building sections held in place by the sur= xoundingandni-utually perpendicular'joiningand coupling bars situated in groovesalongthe edges of the sections;

Fig; lc-is' an enlarged "fragmentary perspective of a typical building-section showing thejoining and coupling-bars in place in the grooves;

Fig. 2;a:horizontal sectional viewoi a junction between *joining'and rail bars in the skeleton on" anenlarged scale,

Fig: 3; atransversesectional view of a coupling bar on the "line III'-III of Fig. 2,

Fig. 4, a sectional view similar to that illustrated in. Fig; 2' but relating to a further embodiment;

Fig. 4ais a. transverse section showing the construction of the joining bar and surrounding half postsgthe section being taken at a point axially of the connection point between adjacentv coupling bars shown in Fig. 4;

Fig. 5", an end view of'a joining bar, of the latter embodiment,

Fig. 6; a view similar to Fig. 2'and illustrating a further embbdimentofa screw connection in.

the skeleton,

Fig. 7; a transverse sectional view on the line VII -VIL of Fig. 6',

Fig. 81 a view of an assembling tool in a posi; tionin the inner of a couplingbar.

Fig. 9,. an end viewof the tool,

Fig. 10, a horizontal sectional view of the wall illustrated .in Fight and taken at the connectionplace between two horizontal skeleton. elements and a .vertical' skeleton element, this view illustrating a modified construction for interconnecting, the elements,

Fig. 10a, a. perspective View of a transverse skeleton element atthe connection place,

Fig. 11 a vertical section corresponding. to Fig. 10,

Fig, 12;.and'12a, perspective views oftwo different embodimentsfor the coupling members used'in Fig. 10 and 11,. on anenlarged scale Fig. 13 and 14, a vertical andhorizontal section corresponding. to Fig. 10 andll respectively butrelating to a different embodiment of the,

coupling members,

Fig. 15, ,an end view ofa building section constructed'as ab'eam,

Fig: 16; a. perspective view of" a similar beam having edge elements,

Fig; 17, a sectional view on the line XVII- xvnror Fig. 15;

1 ing section constructed as a box beam,

Fig. 19, a vertical section at the connection place between two wall sections and a floor section constructed as a beam,

Fig. 20, an elevation of a part of a roof,

Fig. 21, a sectional view of a roof covering on an enlarged scale, and

Fig. 22,'a vertical section of a roof at the connection place between two roof sections.

It is clear from the perspective view of the assembled building illustrated in Fig. 1 that the building comprises a base a, floor sills b supported thereby and a skeleton c thereon which is enclosed in and connects the building sections (1 forming the walls. The roof e consists of sections which are kept together by a skeleton in the same way as the building sections d of the walls. dows by 9. Situated at the points of connection between the skeleton elements there are coupling members which are represented by an undulated line h. Various possibilities of constructing the connections are illustrated by way of example in the following figures.

Fig. 1a is intended to illustrate the principle of assembling a number of building sections and, for the sake of simplicity represents a wall or part of a wall of the building. The same principle, however, is used in assembling the floor, roof or other building structures. The wall consists of a number of building sections 2, 4, 6, 8 which are kept together by means of the skeleton consisting of joining bars I6, [2 and coupling bars l4, l6.

Two coupling bars are connected with each other by a connection member extending through the joining bar Iil or [2 (Fig. 1a) situated between the ends of the coupling bars. The joining bars I0, 112 are arranged so as to have their joined ends in a non-registering position relatively to the point of connection between the coupling bars, 1. e. above or below orlaterally of this point.

In the embodiments illustrated in Figs. 2-8 the member connecting the adjoining ends of adjacent coupling bars to maintain the same in an end-to-end relationship comprises a wood screw.

A door is designated by f and two win- Each of the couplmg bars consists of two wooden battens or rods I8, 20 (Fig. 3) each having three sides plane and the forth side profiled. This side is formed so as to have a groove 22in one edge and a tongue at the other edge and a semicircular channel therebetween. If two such wooden battens are assembled so as to have their profiled sides in engagement with each other I and are connected for example by gluing, a coupling bar having a central prorlled channel 26 will be obtained. A cylindrical chamber 28 having a diameter equal to or greater than the diameter of the screw head and having a depth equal to the length of the screw is bored in one end of the coupling bar. The wood screw 29 is mounted in this chamber.

The chamber is.

closed by a cylindrical wooden plug 30 introduced In assembling two coupling bars [4, I6 and a joining bar I0 (Fig. 2) a screw driver 38 is introduced into one end of the coupling bar. The

outer portion of the driver, the blade, has the transverse section thereof formed to fit into the profiled channel in the bar. As a result the driver cannot be rotated until the blade has been advanced into the chamber 23 which is disposed in the other end of the coupling bar and in which the wood screw 29 is inserted. The driver will be directed exactly towards the screw by the central cylindrical portion of the channel 26 whereby the mounting and dismounting operations are facilitated. By a channel 40 bored in the joining bar l0 (Fig. 2) and having a diameter equal to or greater than the diameter of the screw threads the wood screw is advanced and will engage the other coupling bar H1 in the end of which. the cylindrical, central portion of the channel 26 has a diameter equal to or greater than the diameter of the screw core. When screw 29 is screwed into the end of coupling bar 14 the two coupling bars as well as the joining bar are secured to each other.

Thus it is characterizing for the coupling bar that it is composed of two complementary profiled interconnected wooden elements having a channel for the introduction of a screw driver and enclosing a rotatable wood screw which is entirely embedded and concealed within the coupling bar. However, it is possible to construct the coupling bar as a single wooden rod, a through channel being bored in the centre thereof for the screws and plugs to be mounted as described.

Alternatively, the coupling bar may be provided with a metallic plug in the form of a screw threaded sleeve or the like in one or both ends instead of a wooden plug. This is illustrated by way of example in Fig. 4. The plug 42 in one end of one coup-ling bar [6 is provided with a circular channel 44 having the diameter equal to or greater than the diameter of the coupling threads as in the wooden plug 36- described hereinbefore. A similar plug 46 which has inner screw threads is mounted in the opposite end of the other coupling bar I4. These metallic plugs may be cylindrical or conical. The screw consists of a machine screw having a fiat head.

The coupling bar may be square or circular in cross section and be surrounded or covered wholly or partly by pressed sheet steel or iron, iron tubes or the like. In Fig. 6 and 7 there is illustrated a bond in which the coupling bars have a circular section and a jacket consisting of a metallic tube 50, and a wooden core 52 with a profiled central channel. 7

The joining bar forms a tightening and consurround the joining bar. Two surfaces of the joining bar are smooth according to Fig. 2 whereas the two other surfaces are provided with the groove 36 in which the tenon or tongue 34 situated at the ends of the coupling bars is inserted.

In order to facilitate the introduction of the joining bar into the groove in the building section (for example 4 in Fig. 2) and also the engagement with adjacent building sections (for example 6 in Fig. 2) the joining bar may be the channel in the joining bar and secures the joining bar in a definite position between the necting member between building sections which i two; coupling bars as as results of tightening the may be connected with each other or with asurrounding: buildingcsection.

The joining. bars may. have circular section and consist of tubes of iron: or other metal (Fig.- 6). being constructed-in the samemanner as the coupling bars.

Plates of wood, artificial mass orth'e like may. be fitted into the skeleton consisting. of the join-. ingrand couplingbars to form buildings :accordingto the so called plate system.

Post structures can be constructed by. thisskeleton system by using. two so called halfposts 56, 58 (Figs. 4. and 4a). which-constitute the sides of two separate building sections. and

areassembled together with. a joining bar 80.

The sides. of the half-posts facing each other-are formed with a groove to receive the joining bar. When the half-posts are put together and enclose the joining bar, the jointtherebetween will have no through hole. Also in Fig. 4 the joining bar is. presented with. a form tapering from the centre towards the edges whereby. the joining bar ma be easilyintroduced into the groove of the, half-post. The joint is tightened when two half-posts are pressed together-by screwing because the maximum thickness of the joining bar'will be simultaneouslysituated exactly in the joint 62 between the two half-posts.

Theposts are pressed together by tightening the screws disposed in the coupling bars M, !6 as hereinbefore described.

At the top and the bottom the half-posts may.

be confined by or connected with horizontal bars having the same profile asthat of the half-post.

Where. the joining bar is surrounded by a half-post having tenon holes in which the two ends of the coupling bars. are introduced and glued fast or secured in any other way or the ends of the coupling bars are formed as tenons,

no groove is required in the joining bar and no.

tenonor tongue in the ends of the coupling bars. In such case the half-post is formed so as to prevent, any through joint at the point of connection between the coupling bar and the joining;-bar. According to Figs. 4- and 5 the ends of the. coupling bars (Fig. 5) are provided with a cylindrical tenon 64 which engages a correspondinghole in the half-post.

Such elements as are composed of half-posts and inwhich joining and coupling bars form a skeleton structure as stated above may be used in the production of buildings according to a so called post system. Afterwards panels, plates, artificial mass fillers, and so on may be introduced thereinto. In Fig. 4 a panel 66 is shown in connection with the assembled half-posts 55,

ing-.element asdescribedno through joint is obtained at the point of connection between the coupling bar and the joining bar.

Buildings according tothe so called block system may be produced by means of such composed building sections of panel, artificial mass, filler and .so on which enclose coupling bars forming a skeleton, structure together with joining bars as described above.

The screw driver as used when coupling bars and joining bars are connected with each other consists of the driver blade 10, the driver stem I2 and the driver handle 14 (Fig. 8). Therdriver blade is profiled and formed so as to be easily.

passed through the profiled channel in the coupling bars I6 and is of such a length that when the screw 29 is advanced into position the driver may be rotated in the inner of the screw chamber 28. The diameter of the stem 12 is such as to allow easy displacement in the channel of the coupling bar the central aperture of which has a diameter equal to the diameter of the screw core. The diameter of the stem is equal to or less than the diameter of the screw core. The stem has such a length that in the screwing op.- eration the handle 14 is situated beyond one end of the coupling bar l6 whereas the driver blade is positioned at the screw at. the other end of the coupling bar. The driver handle may be con.- structed as a separate key having one or more square holes 16 fitting upon the end of the driver stem formed in the corresponding way (Fig. 9).

The order of assembly of the several building sections to form a wall is as follows: With reference to Fig. 1a,. the building sections are numbered 2, 4, 6 and 8 and are assembled in that sequence. Starting from the left, the four sections numbered 2, are arranged. each above the other; with the horizontal coupling bars 16 in place. Joining bars l0 and 12 are then set in a place along the right, sides of the sections 2 and the two bars in and. I2 joined: in; end-to-end relation by tightening'screw wll with a screw driver inserted through thebore in the bar. Next the four building sections 4 with the coupling bars M are set in place against the right sides of the sections 2 thus enclosing 'thejoining, bars l8, 12. The leftendof each, of? the coupling bars l4 constructed' in the manner shown in Figs. 2 or 4. contains a screw, these-being numbered ish-4G5 on the drawing; and. aretightened in sequence by pushing the shank of the screw driver 1 through the channel 26 of the bars M until the screw is engaged. Joining bars l0, I2 are next fittedin placealong the rightsides of the building sections and connectedby screw 456. The building sections 6 and Snarethen. assembled in the. sameimanner assections i and the screws 40I'-4l6 are. tightened in the order of their numerical sequence. Itisto be noted that screws Mill, 466, and 4l2 woul'dof: course not be used in cases where thesvertical joining bars extend for; the entire height of the wall assembly as indicated by joiningbar I01" located at the extreme. right; of'the assembly;

Sometimes it is desired toconnect two coupling bars and a joining bar situated therebetween in the skeleton system in-a. manner enabling an elimination ofa driver extending through the entire'coupling bar from one end thereof to the other. Two difierentembodiments of connections for this purpose are illustrated in Figs. 10-12 and 13-15 respectively.

According to Figs. 10 and 11 the two building,

ends thereof in grooves in the facing edges of the building sections 4 and 6 in the manner described hereinbefore. The coupling bars I4 and I6 are connected by a releasable hook bond comprising a hook-like coupling member 80 which is attached to the end surface of the bar 14 by a screw 82, and another hook-like coupling member 84 having a construction similar to that of the first mentioned member and engaged therewith. The member 84 is secured to the bar I5 by a screw 86. The hook-like members are situated, in their mounted position, within an aperture 88 which is provided in the joining bar I0 (Fig. 100.).

The hook member as illustrated in Fig. 12, consists of a plate 90 having a hole for mounting the screw 82 and a flange 92, projecting from oneedge, a gripping portion 94 extending in spaced relation to the plate 90 parallel therewith. The gripping portion has an oblique side 96 facing the plate so that the gripping portion tapers towards its outer edge. A wedge-shaped space 97 is present between the gripping portion 94 and the plate 90. Opposite to the screw hole in the plate 90 the gripping portion is provided with an aperture 98 through which the screw is available.

As illustrated in Fig. 12a the front edge of the flange 92 is provided with a slot 99 extending below the aperture 98. Formed on the plate there is also a projection I00 which suitably tapers from its base and outwardly. This projection is adapted to engage the slot 99 in the other hookshaped coupling member when two such members are brought to engage each other'in a connecting relation. The projection I00 serves as a guide preventing lateral displacements between the coupling members.

When a coupling member of the construction illustrated in Fig. 12 is to be connected with another similar coupling member, this is effected by bringing the latter member in a turned-down position, i. e. with the thin outer edge of the gripping portion 94 turned downwards to engage the former member from above so that the gripping portion 94 of one member 80 enters the wedge-shaped space 91 between the gripping portion 94 and the plate 90 of the other member 80a (Fig. 11), the oblique surfaces 96 of the two members engaging each other. A good wedgelike engagement is thus obtained, and the coupling members have a tendency of moving the ends of the coupling bars to which they are secured towards each other as the gripping portions 94 are being brought further into the wedge-like spaces (Fig. 11). The aperture 88 of the joining bar continues upward with a cavity 89 which enables introduction of the coupling member 80a above the coupling member 80 so that it may be deposited to engage the latter.

Where the coupling members are provided with guiding projections I00 as illustrated in Fig. I2a. care should be taken during thev coupling operation that the projection of one member engages the slot 99 of the other member thus effecting also a lateral locking relation.

In the embodiment illustrated in Figs. 13-14 the coupling between the coupling bars I4, I6 comprises partly a rotatable locking hook I02 having a shaft I04 journalled in a bracket I06 on one coupling bar and partly a stationary locking member secured to the other coupling bar and being formed so as to enable the rotatable locking hook to engage it and effect a locking relation. The locking hook consists of a plate attached to the shaft I04 and having its periphery shaped spirally and provided with a corresponding flange III]. This flange or rim begins at an edge H2 of the plate and from this edge runs spirally at a radial distance from the shaft I04 which decreases successively. The locking portion I08 is provided with a fork-shaped head the shanks II2 of which are provided with inwardly directed projections II4 the opposite faces of which are disposedin such a distance from each other that the plate-shaped portion of the locking hook is free to be introduced therebetween simultaneously as the peripheral flange IIO can be advanced between the fork shanks at the inner side of the projections. The locking portion I08 is further provided with a screw-threaded stem 6, by means of which it is screwed and fixed into the coupling bar I4. The bracket I06 is formed as a clamp for the locking hook I02 and is secured to the bar I6 by a screw H8. The shaft I04 of the locking hook is carried in upwardly open slots I20 in the shanks of the bracket. In one end of the bar I6 there is a cavity I22 in which the bracket I06 is fitted, and corresponding cavities I24 may be present in the building section 6 if needed to get suflicient place for the locking hook.

Figs. 15-16 illustrate building sections constructed as beams or girders and contemplated to be included in a building structure according to the invention. Such a beam or girder may form an intermediate floor or ceiling in a building but may also be used as a Wall section.

The girder shown in Fig. 15 has its web constructed as a number of wooden bars 202 in spaced relation to one another, the flanges consisting of battens 204 which are suitably notched and are mounted in such position on the bars as to have their direction of fibre extending transversely to the wooden bars. The wooden bars are fixed to the battens, for example as shown, by means of a dove-tail bond 206, and thus the entire element has substantially the qualities comparable with those of an I-girder.

To enable connection of two girder type building sections of this type positioned in lateral engagement with each other and with the ends of the bars 202 of the various sections opposite to each other, the bars are provided with longitudinal channels 208 which suitably extend wholly through the bars and contain suitable connection means such as a screw or book in one end of the bar and a corresponding screw' threaded sleeve or bore, hook or loop in the other end. The channel may be formed with such a I section that a suitable tool such as a screw-driver can be inserted and guided therein when the connection is to be established. The detailed construction of the connection means may be as illustrated in Figs. 2, 4, 6 or l0, 11 or 13, 14.

As an alternative or supplement of these connection means, reinforcing irons adapted to strengthen the girder may be inserted in all or some of the channels in the bars.

To enable suitable connection of the girder or beam with similar or different building sections positioned in planes which form an angle with the plane of the girder, the girder may be provided with edge pieces or projections 2I0 at the flange edges parallel with the wooden bars as shown in Fig. 16. The flange edges are countersunk and secured in grooves in the edge piece.

The ends of the webs 202 may be arranged v ith edge pieces 2I2 according to Fig. 18 so that the entire girder or beam forms a closed box. The

outer side of the edge piece 2I2 may have longhor beamhav-ing a web 202, flanges 204and an edge piece or projection 2 l according to the invention on one hand and a pair of other building sections 2 I 8, 220 extending in a plane at right angles to that .of. the girder or beam on the other hand. The girder or beam may form part of a floor-ing in abuilding in which the section2l0 forms part of..a wall in an upper floor and the section 220 forms part or" a wall in a lowerfloor. Thebuilding .sections 2H3 and220 may be substantially constructed as the girder or beam. Numeral 222. designates joining bars between the edge element.2l0 and the coupling bars in the wall sections'2l8, 220.

Where the girder or beam is included as a part of-for example a flooring or wall of a building it maybe provided witha covering of any suitable kind produced for example by painting, papering and so on.

Figs. 20-22 illustrate details of a roof which may be included in a building construction according to the invention. The roof comprises a number of sections 302 which suitably extend from the roof-tree to the lower edge of the roof and are separated by joints 304 which are formed between the edges of the sections positioned side by side. The sections are suitable to manufacturing in a factory. For example thev n'ay consist of tongue and groove connected battens 308 and are each provided with a protecting covering 308 on the top and are produced with this covering in their finished state in the factory. The battens 306 are kept together by transverse bars 301 having connection means inserted therein to enable connection of the section with other sections included in a roof. The bars and the connection means are included in the finished section as produced in the factory. Generally the bars are shorter than the breadth of the roof section so that between each pair of adjacent sections there is a space between the bar ends to receive a roof truss element 309 or the like supporting the section. A coupling member 31! extends through the roof truss element between the bar ends. This coupling member while shown as a wood screw may also be of any of the other types described in connection with Figs. 4, 6, or 10, 11. or 13, 14.

The covering consists of a layer 3l0 of asphalt or the like (Fig. 21) and a foil 3l2 of metal, cellophane or the like embedded therein. At the top there is a thin layer 3M of crushed mineral raw substance of any suitable colour for example crushed gravel, potstone chips, or the like. The asphalt to be employed should suitably have a low point of plasticity so that it may be defo med to a certain extent without the generation oi. cracks. According to certain tests the asphalt generally is porous to a certain extent and as a consequence is not entirely sealing. The necessary sealing condition is thus obtained by the foil which may advantageously consist of a aluminium foil. To prevent breaking thereof in. case of stresses generated due to displacement". o the support at changes of te perature and moisture the foil is folded or undulated.

In addition to the foil the covering may contain or have a support consisting of a layer of jute-cloth, wire net or the like.

To prevent water from penetratin into the joints between the roof panel sections the marginal portions thereof which after mounting the section extends from the roof tree and downwards along the roof, i. e. the marginal portion close by the joints 304 may be-projecting upwards and be formed to Support a sealing strip 3l6 of for example sheet metal as illustrated in Fig. 22. Said sealing strip may be substantia ly T-siaped in cross section having the portioncorreponding to the vertical part of the T introduced into the space between the panel sections, where s the remainder thereof extends as a roof above the joint and the adjacent marginal portion of the panel sections. The sealing strip may be made from a single strip ofsheet metal which has been doublefolded along a longitudinal line whereupon one of the folded shanks has been bent to stand at right angles to the other.

What I claim is:

1. Awall comprising er -plurality of abutting rectangular wooden panels having grooves in the longitudinal and transverse "edges thereof, and a wooden skeleton connecting said panels together in edge-to-edge relation to form an unbroken surface, said skeleton-comprising"Wooden join-ing bars disposed in the grooves along one pair of opposite edges of said panels, wooden coupling bars disposed in the grooves along the other pair of opposite edges of said panels, said coupling bars being sectionalized to provide a joint therebetween at each joining bar and. with the adjoining ends of adjacent coupling bars abutting opposite sides of the joining bar, each said coupling bar including an axial channel extending longitudinally therethrough, the configuration of said channel in a plane normal to the longitudinal axis thereof including a circular central portion and diametrally opposite slots extending therefrom to permit guided insertion of the shank and blade of a screw driver, a headed screw concealed from View, and means retaining the screw head in said channel at one end of said coupling bar, the shank of said screw extending outwardly of the bar end through an aligned transverse aperture in said joining bar and threadedly engaged with the adjoining end of the adjacent coupling bar.

A wall as defined in claim 1 wherein each said coupling bar is comprised of two wooden strips joined longitudinally in face-to-face relation, said strips each being provided with co-registering longitudinal grooves establishing the said channel in the bar.

3. A wall as defined in claim 1 wherein one end of the channel in each said coupling bar terminates in a screw chamber, and said screw head retaining means is comprised of a bored plug secured within said chamber, the shank of said screw extending outwardly through the bore in said plug and the screw head being retained against longitudinal displacement by said plug.

4. A wall comprising a pair of grooved panels arranged in edge-to-edge relation to form an unbroken surface and means securing said panels together in edge-to-edge relation, said securing means comprising a pair of bars arranged in end-to-end relation in the grooves of said panels, each said bar including an axial channel extending longitudinally therethrough, the configuration of said channel in a plane normal to the longitudinal axis thereof including a circular central portion and diametrally opposite slots extending therefrom to permit guided insertion of the shank and blade of a screw driver, a headed screw concealed from view within said bars joining adjacent ends of said bars in end-to-end 1 1 relation, and means retaining the screw head in the channel of one of said bars at one end thereof for engagement with a screw driver when inserted through the channel from the other end of the bar, the shank end of said screw projecting outwardly from the bar end and threaded into the adjacent end of the other of said bars.

CARL AUGUST AJNE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 609,685 Leonard Aug. 23, 1898 656,314 Beerbower Aug. 21, 1900 724,638 Wheeler, et a1 Apr. 7, 1903 1,111,131 Broughton Sept. 22, 1914 1,165,049 White Dec. 21, 1915 1,246,281 Knack Nov. 13, 1917 1,736,373 Seeger Nov. 19, 1929 1,960,575 Davison May 29, 1934 Number 20 Number 12 Name Date Brown Aug. 14, 1934 Williams Feb. 12, 1935 Venzie May 12, 1936 Venzie July 21, 1936 Mueller Dec. '14, 1937 Killion Apr. 19, 1938 Gurber May 3, 1938 Mackin Apr. 18, 1939 Raybould Sept. 10, 1940 Gunnison Oct. 15, 1940 Heanue May 20, 1941 Guignon July 15, 1941 Mason May 11, 1943 Teague et a1 Mar. 28, 1944 Sheldon Nov. 7, 1944 Smith 1 June 4, 1946 FOREIGN PATENTS Country Date Great Britain Dec. 29, 1932 Germany Apr. 21, 1936 

